<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>

    </style>

    <script src="./react/react.development.js"></script>
    <script src="./react/react-dom.development.js"></script>
    <script src="./react/babel.min.js"></script>
    <script src="./react/prop-types.js"></script>
</head>
<body>
<div id="app"></div>
<script type="text/babel">

    //JSX=JS+xml、
    let app = document.querySelector('#app');
    let root = ReactDOM.createRoot(app);

    class Welcome extends React.Component{
        state={
            msg:'hello',
            count:0
        }

        //setState设置响应式
        handleClick2 = () =>{
            this.setState({
                msg:'hi',
                count:1
            })
        }

        render(){
            return(
                <div>
                    <button onClick={this.handleClick2}>点击</button>
                    {this.state.msg}
                </div>
            )
        }
    }

    let info = {
        msg: 'hi react',
        username: 'lwj',
        age : '20'
    }

    let element = (<Welcome msg = "hi react class"/>)
    element = (<Welcome />)

    root.render(element);

</script>
</body>
</html>